Is this value a JS FinalizationRegistry? This module works cross-realm/iframe, and despite ES6 @@toStringTag.
```js var isFinalizationRegistry = require('is-finalizationregistry'); assert(!isFinalizationRegistry(function () {})); assert(!isFinalizationRegistry(null)); assert(!isFinalizationRegistry(function* () { yield 42; return Infinity; }); assert(!isFinalizationRegistry(Symbol('foo'))); assert(!isFinalizationRegistry(1n)); assert(!isFinalizationRegistry(Object(1n)));
assert(!isFinalizationRegistry(new Set())); assert(!isFinalizationRegistry(new WeakSet())); assert(!isFinalizationRegistry(new Map())); assert(!isFinalizationRegistry(new WeakMap())); assert(!isFinalizationRegistry(new WeakRef({})));
assert(isFinalizationRegistry(new FinalizationRegistry(function () {})));
class MyFinalizationRegistry extends FinalizationRegistry {} assert(isFinalizationRegistry(new MyFinalizationRegistry(function () {}))); ```
Simply clone the repo, npm install
, and run npm test